Agricultural Animal Health Program

Symptoms and risks of foodborne illness

People who are at risk for infection with E. coli O157, salmonella species, or campylobacter species include anyone drinking inadequately treated water or eating undercooked or mishandled food products, and those who are in contact with farm animals or domestic pets. The most common food vehicles for salmonella include eggs, poultry, meat, and meat products. Salmonella also has been found […]

Preventing salmonellosis at home

Salmonellosis is a disease shared by animals and humans, and several outbreaks of salmonellosis in Washington cattle have lead to human illness. People in direct contact with cattle are not the only ones who can become sick. Indirect contact with cattle can occur when someone handles products like unpasteurized milk or touches boots contaminated with […]


Mastitis is an inflammation of the mammary gland. It is a disease that can affect production and its quality on dairies. This research group focuses on the examination and development of new methods for controlling mastitis, especially mastitis caused by Staphylococcus aureus. DNA “fingerprinting” helps researchers trace this pathogen from reservoir to fomite to host.  Following […]


There are three major groups of salmonella: host-specific (primarily infects one species of animal), host-adapted (can infect several species but are adapted to live in one), and unadapted serovars with no host preference 1. The foodborne pathogens we study are in the last two groups. Salmonella is a bacteria which causes a foodborne diarrheal illness in humans. […]

Foodborne disease overview

Primarily, we study the foodborne pathogens Escherichia coli O157:H7 (O157), Salmonella enterica serovar typhimurium definitive type 104 (DT104), and Campylobacter jejuni. These bacteria inhabit the gastrointestinal tracts of a large variety of species. Water trough sediments, soil, and animal bedding can also harbor O157 and DT104. This wide range of habitats and reservoirs, ranging from stagnant ponds to insect guts […]

The role of feed and water in on-farm infection

A current study funded by an FDA grant traces the path of E. coli O157 and Salmonella on farms. Fecal, feed and water samples will be taken from 24 dairies over a 2-year period. These samples will be cultured for both E. coli O157 and Salmonella species. The prevalence of pathogens in the feed and water will be compared to […]

E. coli

Generic E. coli is a normal flora resident of the bovine gastrointestinal tract. It poses little danger as a foodborne disease. However, the O157 serotype of E. coli can be extremely dangerous to young, old, and immunocompromised individuals. E. coli O157 is a transient resident of cattle. It can be found on most cattle farms […]